5962R9166702V9A - Defense Logistics Agency

LM2941QML

August 25, 2009

1A Low Dropout Adjustable Regulator

General Description

The LM2941 positive voltage regulator features the ability to

source 1A of output current with a typical dropout voltage of

0.5V and a maximum of 1V over the entire temperature range.

Furthermore, a quiescent current reduction circuit has been

included which reduces the ground pin current when the dif-

ferential between the input voltage and the output voltage

exceeds approximately 3V. The quiescent current with 1A of

output current and an input-output differential of 5V is there-

fore only 30mA. Higher quiescent currents only exist when the

regulator is in the dropout mode (VI − VO ≤ 3V).

Originally designed for vehicular applications, the LM2941

and all regulated circuitry are protected from reverse battery

installations or two-battery jumps. During line transients, such

as load dump when the input voltage can momentarily exceed

the specified maximum operating voltage, the regulator will

automatically shut down to protect both the internal circuits

and the load. Familiar regulator features such as short circuit

and thermal overload protection are also provided.

Features

■Available with radiation guarantee

—ELDRS Free 100 krad(Si)

■Output voltage adjustable from 5V to 20V

■Dropout voltage typically 0.5V @ IO = 1A

■Output current in excess of 1A

■Trimmed reference voltage

■Reverse battery protection

■Internal short circuit current limit

■Mirror image insertion protection

■TTL, CMOS compatible ON/OFF switch

Ordering Information

NS Part Number SMD Part Number NS Package Number Package Description

LM2941WG/883 5962-9166701QYA WG16A 16LD Ceramic SOIC

LM2941WG-QMLV 5962-9166701VYA WG16A 16LD Ceramic SOIC

LM2941WGRLQMLV

ELDRS FREE (Note 10)

5962R9166702VYA

100 krad(Si) WG16A 16LD Ceramic SOIC

LM2941 MDE

ELDRS FREE (Note 10)

5962R9166702V9A

100 krad(Si) (Note 1) Bare Die

Note 1: FOR ADDITIONAL DIE INFORMATION, PLEASE VISIT THE HI REL WEB SITE AT: www.national.com/analog/space/level_die

Connection Diagrams

16-Lead Ceramic Surface Mount Package

20158532

Top View

See NS Package Number WG16A

LM2941QML 1A Low Dropout Adjustable Regulator

Equivalent Schematic Diagram

20158501

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LM2941QML

Absolute Maximum Ratings (Note 2)

Input Voltage (Survival Voltage, ≤ 100ms) 60V

Internal Power Dissipation (Note 3) Internally Limited

Maximum Junction Temperature 150°C

Storage Temperature Range −65°C ≤ TJ ≤ +150°C

Lead Temperature (Soldering, 10 seconds) 300°C

Thermal Resistance

θJA

Ceramic SOIC (Still Air) 122°C/W

Ceramic SOIC (500LF/Min Air Flow) 77°C/W

θJC

Ceramic SOIC (Note 4) 5°C/W

Package Weight (Typ)

Ceramic SOIC 360mg

ESD susceptibility to be determined. (Note 5) 500V

Recommended Operating Conditions

Maximum Input Voltage 26V

Temperature Range −55°C ≤ TA ≤ 125°C

Quality Conformance Inspection

Mil-Std-883, Method 5005 - Group A

Subgroup Description Temp °C

1 Static tests at 25

2 Static tests at 125

3 Static tests at -55

4 Dynamic tests at 25

5 Dynamic tests at 125

6 Dynamic tests at -55

7 Functional tests at 25

8A Functional tests at 125

8B Functional tests at -55

9 Switching tests at 25

10 Switching tests at 125

11 Switching tests at -55

12 Settling time at 25

13 Settling time at 125

14 Settling time at -55

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LM2941QML

LM2941 Electrical Characteristics

DC Parameters

The following conditions apply, unless otherwise specified.

DC: 5V ≤ VO ≤ 20V, VIN = VO+5V, CO = 22µF

Symbol Parameter Conditions Notes Min Max Unit Sub-

groups

VRef Reference Voltage 5mA ≤ IO ≤ 1A 1.237 1.313 V 1

1.211 1.339 V 2, 3

VRLine Line Regulation VO + 2V ≤ VIN ≤ 26V, IO = 5mA (Note 8) 10 mV/V 1, 2, 3

VRLoad Load Regulation

50mA ≤ IO ≤ 1A, VIN = 10V,

VOUT = 5V (Note 8)

10 mV/V 1, 2, 3

50mA ≤ IO ≤ 1A, VIN = 25V,

VOUT = 20V

10 mV/V 1, 2, 3

IQQuiescent Current

VO + 2V ≤ VIN ≤ 26V, IO = 5mA 15 mA 1

20 mA 2, 3

VIN = VO + 5V, IO = 1A 45 mA 1

60 mA 2, 3

VDO Dropout Voltage

IO = 1A 0.8 V 1

1.0 V 2, 3

IO = 100mA 200 mV 1

300 mV 2, 3

ISC Short Circuit Current VIN Max = 26V 1.6 3.5 A 1

1.3 3.7 A 2, 3

Maximum Operational Input

Voltage

(Note 7) 26 VDC 1, 2, 3

Reverse Polarity DC Input

Voltage

RO = 100Ω, VO ≥ -0.6V (Note 6) -15 V 1, 2, 3

VTH On ON/OFF Threshold Voltage ON IO ≤ 1A (Note 6) 0.8 V 1, 2, 3

VTh Off ON/OFF Threshold Voltage OFF IO ≤ 1A (Note 6) 2.00 V 1, 2, 3

ON/OFF Threshold Current VON/OFF = 2.0V, IO ≤ 1A 100 µA 1

300 µA 2, 3

AC Parameters

The following conditions apply, unless otherwise specified.

AC: 5V ≤ VO ≤ 20V, VIN = VO+5V, CO = 22µF

Symbol Parameter Conditions Notes Min Max Unit Sub-

groups

Maximum Line Transient VO Max 1V above nominal VO, RO

= 100Ω, t ≤ 100mS

60 V 4, 5, 6

Reverse Polarity Transient Input

Voltage

t ≤ 100mS, RO = 100Ω -50 V 4, 5, 6

RR Ripple Rejection ƒO = 1KHz, 1 VRMS, IL = 100mA (Note 9) 0.02 %/V 4

ƒO = 1KHz, 1 VRMS, IL = 100mA (Note 9) 0.04 %/V 5, 6

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LM2941QML

DC Drift Parameters

The following conditions apply, unless otherwise specified.

DC: 5V ≤ VO ≤ 20V, VIN = VO+5V, CO = 22µF

Delta calculations performed on QMLV devices at group B , subgroup 5.

Symbol Parameter Conditions Notes Min Max Unit Sub-

groups

VRef Reference Voltage 5mA ≤ IO ≤ 1A -25 +25 mV 1

Note 2: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is

functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics. The guaranteed

specifications apply only for the test conditions listed. Some performance characteristics may degrade when the device is not operated under the listed test

conditions.

Note 3: The maximum power dissipation must be derated at elevated temperatures and is dictated by TJmax (maximum junction temperature), θJA (package

junction to ambient thermal resistance), and TA (ambient temperature). The maximum allowable power dissipation at any temperature is PDmax = (TJmax - TA)/

θJA or the number given in the Absolute Maximum Ratings, whichever is lower.

Note 4: The package material for these devices allows much improved heat transfer over our standard ceramic packages. In order to take full advantage of this

improved heat transfer, heat sinking must be provided between the package base (directly beneath the die), and either metal traces on, or thermal vias through,

the printed circuit board. Without this additional heat sinking, device power dissipation must be calculated using θJA, rather than θJC, thermal resistance. It must

not be assumed that the device leads will provide substantial heat transfer out of the package, since the thermal resistance of the lead frame material is very

poor, relative to the material of the package base. The stated θJC thermal resistance is for the package material only, and does not account for the additional

thermal resistance between the package base and the printed circuit board. The user must determine the value of the additional thermal resistance and must

combine this with the stated value for the package, to calculate the total allowed power dissipation for the device.

Note 5: Human body model, 1.5 kΩ in series with 100 pF.

Note 6: Functional test go-no-go only.

Note 7: Condition for VIN

Note 8: Limit = mV per volt of VO.

Note 9: %/V = % of VIN per Volt of VO.

Note 10: These parts are tested on a wafer by wafer basis at high and low dose rates according to MIL-STD-883 Test Method 1019 Conditions A and D with no

enhanced low dose rate sensitivity (ELDRS). Pre and post irradiation limits are identical to those listed under AC and DC electrical characteristics.

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LM2941QML

Typical Performance Characteristics

Dropout Voltage

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Dropout Voltage vs. Temperature

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Output Voltage

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Quiescent Current vs. Temperature

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Quiescent Current

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Quiescent Current

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LM2941QML

Line Transient Response

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Load Transient Response

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Ripple Rejection

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Output Impedance

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Low Voltage Behavior

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Low Voltage Behavior

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LM2941QML

Output Capacitor ESR

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Output at Voltage Extremes

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Output at Voltage Extremes

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Peak Output Current

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LM2941QML

Typical Applications

5V to 20V Adjustable Regulator

20158503

Note: Using 1KΩ for R1 will ensure that the input bias current error of the adjust pin will be negligible. Do not bypass R1 or R2. This will lead to instabilities.

* Required if regulator is located far from power supply filter.

** CO must be at least 22μF to maintain stability. May be increased without bound to maintain regulation during transients. Locate as close as possible to the

regulator. This capacitor must be rated over the same operating temperature range as the regulator and the ESR is critical; see curve.

1A Switch

20158506

*** To assure shutdown, select Resistor R3 to guarantee at least 300μA of pull-up current when S1 is open. (Assume 2V at the ON/OFF pin.)

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LM2941QML

Revision History Section

Released Revision Section Changes

08/25/09 A New Release, Corporate format 1 MDS data sheet converted into one Corp. data

sheet format. Added Radiation products to ordering

table. MNLM2941-X Rev 4A1 will be archived.

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LM2941QML

Physical Dimensions inches (millimeters) unless otherwise noted

16LD Ceramic SOIC

NS Package Number WG16A

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LM2941QML

Notes

LM2941QML 1A Low Dropout Adjustable Regulator

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